With the wide-spread use of wireless communication, it has become common that a single apparatus can deal with a plurality of wireless systems. In such a single apparatus, it is desirable to dispose an antenna at an optimum position within the apparatus, in order to enable the apparatus to deal with various wireless systems at any time with no restriction in terms of time or place. Also for the purpose of dealing with a plurality of wireless systems, there is a case of disposing a plurality of antennas within a single apparatus.
On the other hand, on portable terminals exemplified by a cellular phone, a smart phone or the like, size reduction is demanded in addition to increase in functionality. Accordingly, in the apparatus design, it is required to dispose a large number of components within a terminal. While it is required to dispose an antenna at an optimum position for the purpose of dealing with a plurality of wireless systems, there is a case where the antenna cannot be disposed at an optimum position as a result of trade-off with other components.
In this respect, there has been a proposal of adopting a split ring resonator (SRR) antenna which can maintain an excellent characteristic regardless of its mounting position as long as the position is in the periphery of a multi-layered printed board. Such an SRR antenna is disclosed in Patent Literature 1 (PTL1), for example.
The antenna of Patent Literature 1 (PTL1) is shown in FIG. 13. In the antenna 900 shown in FIG. 13, conductor layers 930 and 940 are arranged on the top and the bottom, respectively, of a dielectric layer 920 of a multi-layered printed board 910. Then, by forming openings 931 and 941 and slits 932 and 942 in end regions of the respective conductor layers 930 and 940, split ring parts 951 and 952 are formed. Further, by arranging, within the dielectric layer 920, conductive vias 953 electrically connecting the split ring parts 951 and 952 with each other and a power feeder 954 connected to one of the conductive vias 953, an SRR antenna 950 is formed.